1. Field of the Invention
This invention relates to a bicycle wheel hub, more particularly to a power-generating wheel hub.
2. Description of the Related Art
A power-generating wheel hub, as disclosed in U.S. Pat. No. 7,002,280, includes a bobbin having a tubular body, two flange plates connected respectively to two opposite ends of the tubular body, a plurality of grooves formed in side surfaces of the flange plates, and a coil wound around the tubular body. A plurality of magnetic yoke arms are mounted to the bobbin such that they engage respectively the grooves. Since the grooved structures of the flange plates are adjacent to the winding area of the coil, the coil is easily hooked to the grooves during a winding operation, so that the winding operation of the coil is not smooth. Further, since the grooves in the flange plates determine the number of magnetic poles, and since the grooves are formed fixedly in the flange plates of the bobbin, the number of the magnetic poles is fixed. In order to suit an energy generation requirement, a new mold for the bobbin must be made so that the number of the poles can be increased or decreased according to the requirement. However, this increases the costs of the power-generating wheel hub.